Paul Christ

Integrating MPEG-4 into the Internet

The standard MPEG-4 (ISO/IEC 14496), initially made available as version 1, in October 1998, was published as an International Standard in January 1999. In addition to new compression algorithms for video and audio, the MPEG-4 standard covers new features such as VRML-like scene description together with advanced streaming and user-interaction functions. By not targeting any particular delivery technology, MPEG-4 is open to all kinds of transport or delivery mechanisms. However, when it comes to integrating MPEG-4 with Internet technology, there are still some unresolved issues that this paper is addressing. Firstly, transport solutions for MPEG-4 over IP-based networks, including the Internet, are addressed. The paper then examines the problem of application signalling and describes solutions for Stream Control, especially within the Internet context. Finally, the possibility for integrating MPEG-4 clients with an RTSP server is examined.

Networking Issues in PAGEIN: The N of HPCN

European projects such as RACE 2031 PAGEIN — multimedia supported collaborative supercomputing, simulation and visualization in aerospace research and industry are essentially dependent on networking facilities — locally, nationally and internationally. The paper is going to present measurements carried out in the context of PAGEIN with respect to a variety of performance parameters such as throughput or latency. Results both from local “Gigabit networks” and wide area high-speed networks will be presented.

Improving the radio link layer QoS performance for Bluetooth real-time video communications

This paper investigates the quality of service (QoS) performance over a Bluetooth radio link for real-time video communications. A bit error control algorithm is proposed for protecting the bit error sensitive data of the latest video codecs as well as the compressed protocol headers. Bit errors and erroneous PDU delivery are analyzed in a Bluetooth link. UDP-Lite and robust protocol header compression (RoHC) are used and integrated into the trial testbed. By sacrificing a small amount of bandwidth in the Bluetooth link, simulations have shown a significant improvement in the video quality in terms of PSNR as demonstrated by some sample video images.

Design and implementation of a diffserv enabled HFC system offering Strict QoS support

Widespread deployment of Hybrid Fiber Coaxial (HFC) systems created a new residential access platform upgrading traditional cable TV networks, which were limited to distributed services. This evolution is driven by demand for faster Internet access from customers frustrated by slow telephone line and ISDN modem speeds. As residential traffic with voice and video-intensive content proliferates, the current generation of cable modems, which are oriented towards best-effort traffic, will need to be enhanced with new capabilities to handle the increased bandwidth and quality requirements. To integrate telecom services presenting diverse quality requirements over the same HFC access infrastructure necessitates a degree of isolation of traffic classes. The difficulty of handling finer aggregations because of the limited MAC reservation resources and the cost limitation of residential access make the scalability of the differentiated services architecture as relevant in the HFC access network as in any traffic multiplexer. An implementation integrating IP and ATM and aligning the system to the DiffServ philosophy is presented in this paper. It constitutes an affordable system solution for residential customers enabling the support of QoS-demanding services.

High Performance Metacomputing in a Transatlantic Wide Area Application Testbed

During the last couple of years, a wide variety of tools and libraries have been developed to enable distributed computing and visualisation. This paper presents the technical background and the results of such a project meaned to couple different computational resources. A metacomputing implementation of MPI called PACX-MPI was used to make the applications run on such a cluster. Three applications were used for demonstration purposes. These applications had to be adapted for Metacomputing, to make them more latency tolerant.

Networking Perspectives for Collaborative Supercomputing in European Aerospace Research and Industry

For some years European aerospace industry and research pursue the idea of an ’EASNet’ — an European Aeronautical Supercomputing Network. Within this context, the project RACE 2031 PAGEIN ’Pilot Applications in a Gigabit European Integrated Network’ collects a major part of European aerospace research, some manufacturers and two universities. PAGEINs application environment comprises elements such as supercomputers of different architectures, simulations in computational fluid dynamics (CFD), scientific visualization and cooperative working scenarios including voice and video — to be demonstrated in a high-speed network environment. Using it as a paradigm, the presentation is going to position networking aspects of PAGEIN with respect to history and present state of efforts both within the European aerospace industrial research and CEC level programs towards high-speed network mediated international collaboration.

The CIO Multimedia Communication Platform

Within the context of an european networking project (RACE 2060 CIO) the University of Stuttgart is developing a common “Communication Platform” which can be used for (real-time multimedia) data transmission and runs on top of several operating and transport systems. Primary intention is to allow for development of multimedia applications that make use of advanced networking features which will soon become available. While early implementations of the Communication Platform will have to simulate any features missing in current transport protocols, future advances in network research may be included without a need for changing the service, its programming interface, or any applications relying on the CIO Platform. Beginning with a short overview of the whole project this paper briefly describes the Communication Service and its interface focusing on special characteristics of the CIO Communication Platform.

Public Broadband Networks — Present State and Future Perspectives

Large-scale technical-scientific Simulations in Supercomputer-Network-complexes, exemplified here by the ‘StuttgartTetrahedron’, represent — among others — one of the scenarios to be extended to a national and eventually European scale in order to guarantee the competitiveness of the continent in the long run. Starting from the Stuttgart experiences the present situation and future alternatives for public broadband networks as a prerequisite for such a geographic extension are investigated.

The environment of the Stuttgart tetrahedron

Abstract Large-scale technical-scientific simulations in Supercomputer-Network-complexes, exemplefied here by the ‘Stuttgart Tetrahedron’, represent one of the scenarios to be extended to a European scale in order to guarantee the competitiveness of the continent in the long run. Starting from the Stuttgart experiences the present situation and future alternatives for such a scenario are investigated.